segmentio/analytics.js

Analytics.js is an open-source JavaScript library built by Segment that lets you track user behavior on a website and send that data to many different analytics services at once. Instead of writing separate code for each tool you want to use, such as Google Analytics, Mixpanel, or Facebook Ads, you write a single set of API calls and the library handles routing the data to every destination you have switched on. You can add or remove any service from a settings dashboard without touching your code again. The main idea is a single tracking call that fans out to multiple tools. When a user completes an action on your site, you record that event once, and the library forwards it to whichever services you have connected. The project supports more than 250 destinations, covering categories like email marketing, advertising platforms, session recording, and data warehouses such as Amazon Redshift and Google BigQuery. Sending data to a warehouse also lets you query your user behavior history in SQL without building your own data pipeline. This repository contains a pre-built, standalone version of the library that you can use without a paid Segment subscription. If you need a smaller build with only the plugins relevant to your setup, the project wiki explains how to compile a custom version. The core logic and each integration plugin live in separate repositories under the Segment GitHub organization, so issues can be filed against the right piece. One thing worth knowing: this is the older generation of the library. The README itself links to a newer version called analytics-next as the current recommended path. If you are starting a new project with Segment today, that repository is likely where you should begin. The library is released under the MIT license.